Operation of the Nozomi No. 34 super express bound for Tokyo from Hakata in Fukuoka was discontinued at Nagoya Station following the discovery of the technical problem on Dec. 11. The government's Japan Transport Safety Board has recognized the case as a "serious incident" -- the first time that a problem involving a bullet train has been recognized as such.

Questions have been raised over the fact that the train stayed in service for three hours after the initial discovery of irregularities. About 20 minutes after the train left Hakata Station, at least one crew member noticed a burning smell. As the train approached Okayama Station, a passenger reported to a crew member that the air inside the train was foggy, so maintenance crew boarded the train at Okayama Station. There, they confirmed an abnormal groaning sound, but concluded that it would not affect the safety of the train's operation. Despite an abnormal odor being detected once again near Kyoto Station, the train continued on its way before service was discontinued at Nagoya Station.

Experts have pointed out that if the carriage had been fractured, the train could have derailed. In other words, the situation could have developed into a fatal accident.

Operators of railway systems that transport massive numbers of passengers at high speeds must place top priority on suspending service if irregularities are found. One cannot help but wonder whether high-speed train operators place such a huge priority on punctuality that safety has ended up on the back burner.

The latest case has called into question the attitude of West Japan Railway Co. (JR West), the operator of the troubled Shinkansen train. There should be a renewed effort to raise employees' awareness regarding safety through education and training.

JR West must also shed light on the cause of the problem. Specifically, the railway operator needs to get to the bottom of why the carriage -- made of steel -- cracked, whether it is attributable to the quality of the materials it is made of, or a structural defect such as its design. This is especially important since a spate of wrongdoing by Japanese manufacturers has been recently reported.

It is also essential to examine whether the company's system of servicing and inspecting bullet trains is flawed. The train involved in the incident was made in 2007. JR West conducted a thorough inspection of it in February this year that included disassembling the cars. Furthermore, mechanics carried out a sight inspection of the train in the predawn hours on the day of the incident, but no irregularities were found.

Even excellent, cutting-edge machines and systems cannot be completely free of technical problems. To enhance the safety of trains and the railway system, it is necessary for multiple mechanics to carry out double- and triple-checks. If flaws in the inspection system are found, they must be rectified.

Shinkansen lines are operated by different regional companies in the Japan Railways (JR) group. Operation of the Tokaido-Sanyo Shinkansen Line is divided between Central Japan Railway Co. (JR Central) and JR West. JR Central and JR West should ask themselves whether they have an adequate system of sharing information about irregularities and technical problems involving their trains. The entire JR group must share a sense of crisis.